I do not recommend to try it without a flasher installed and a dump of the flash.
To quote, roughly translated: Hi all, What better than to come back with this kind of news! Our friend and SGK developer releases today the result of hard work. Indeed, in the shadow he worked to bring us a CFW with features interesting and not yet seen the new CFW 4.xx
The basis of this CFW is based on Rogero 4.30 and the 4.21 Rebug CFW which is the most stable and most successful of the moment. He added SGKXMBM + Package Manager for our greatest pleasure. Some files from firmware 4.31 which ensures compatibility for the latest keysets. So you can play your backups favorites without a patch or fix. 4.31 is a spoof includes access to PSN and avoid unintended updates.
Added package SGKXMBM +
Lv1 Lv2 and recompiled.
Patched Peek & POKE
Coldboot game replaced
Theme changed from dynamic watch dogs
Testers and developers: consolehackdev / ZZ / dedalo! Teamsgk/ps3devs; SGK_84
Stay tuned for more PS3 Hacks and PS3 CFW news, follow us on Twitter and be sure to drop by the PS3 Hacks and PS3 Custom Firmware Forums for the latest PlayStation 3 scene updates and homebrew releases!
Also if you are new to all this it is not recommended to install something still in development, so assuming you take the advice from the link above you should then look into ErmaC, Rebug, or Rogero CFW which are more stable than the SGK development versions.
I have a PS3 Slim 320 GB with move and 4.31 firmware on it I want to play backup games on my PS3, so what I need to do ? I have downloaded PS3 CFW 4.31.1 by SGK is under development version but it is a ". pup" file how can I install please anybody tell me step by step I am new to this CFW thing.